-24461950817domain: ZAppears in sequencesG.f. F_1(x) satisfies: x = Sum_{n>=1} F_{n}(x)^n, where the n-th iteration of the g.f. is defined by: F_{n}(x) = F_{n-1}( F_1(x) ) with F_0(x) = x.at n=15A171780